1. Field of the Invention
The present invention relates to a catalyst comprising a porous activated alumina carrier and a catalytically active component of metals of Groups VI B and VIII of the Periodic Table carried thereon, and a process for its production. More particularly, it relates to a catalyst which exhibits a superior catalytic activity in the hydrogenation treatment of heavy oils for desulfurization and removal of heavy metals, and a process for the production of such a catalyst.
2. Description of the Prior Art
Heavy oils such as residual oils obtainable from atmospheric distillation of crude oils or light oils and residual oils obtainable from reduced pressure distillation of crude oils, contain sulfur compounds and heavy metals as impurities. When the heavy oils are to be used as fuels or to be processed to produce light oils, it is necessary to preliminarily remove these impurities.
As a catalyst for the hydrogenation desulfurization of heavy oils, a catalyst is known wherein a metal of Group VI B of the Periodic Table such as molybdenum or tungsten and a metal of Group VIII of the Periodic Table such as cobalt or nickel are supported on a carrier such as alumina. Such a catalyst tends to readily lose its catalytic activity when brought in contact with asphaltenes or heavy metals contained in the heavy oils. Under the circumstances, various studies have been made to improve the catalyst, particularly to improve the physical properties of the alumina carrier.